Indeed -- sometimes Satan will even try to convince you that you communicating with God. Though God is more powerful and will ward off anything that doesn't belong provided you genuinely seek Him.
I used to hold issue with this sort of thing too because it felt like perhaps I was communicating with the dead. But as I got older, prayed more, studied Scripture more, and studied logic behind faith, it makes no sense that that is what it is. Angels aren't the dead. They are creatures of God, in service to God, to help those who are seeking salvation. They themselves pray, and their prayers, in worship to Him, are for those who they they are sent to help.
If asking an angel to pray for us is useless because they can't hear us (which makes no sense, but in any case...) then it is a waste, but not evil. If they indeed CAN hear us (which does make sense) and they do pray (which they do) then asking them to pray for us is not only not a waste, but a good idea, as we should always ask others to pray for us -- both our friends and those in the presence of God, like angels.